Tobacco manufacture



Feb. 17, 1970 I E. ERXLEBEN aT/uu TOBACCO MANUFACTURE v Filed Feb. 7, 1968 ,4 7- raza/70- United States Patent O U.S. Cl. 264-24 16 Claims ABSTRACT oli/THE DISCLOSURE A method and a means for the manufacture of tobacco foil in which a layer of fibres and tobacco dust is formed on a conveyor belt. In order to ensure that the dust settles or otherwise comes to lie `between the fibres on the belt, the fibres are caused to stand upright and on end upon the conveyor belt by the application of an electrostatic field.

The present invention relates to the arrangement of fibrous material and dust-like material in an elongated, flat formation, and more particularly to the production of tobacco foil from tobacco products.

There are a number of prior art methods for the production of such tobacco foil or tobacco paper. One such proposal or method, for the production of a tobacco paper which was free of cellulose not originating from the tobacco material itself, tobacco waste was treated with water and then made into lengt-hs of foil on a paper-making machine. In this method, vwaste products created during the handling of tobacco leaves was chopped up, covered with water and allowed to stand. After being caused to swell by the water, it was treated in conventional papermaking machinery. That is to say, it was first placed in an apparatus to separate the fibres, then sorted into a long-fibred portion and a short or sludge-like portion, the latter not originating from the tobacco plant. The longfibred portion `was then mixed with aluminum hydroxide and then formed into a sort of paper on a paper-making machine. On the lwet part of the paper-making machine the material was treated with a moistening agent, as is conventionally used in the production of tobacco.

In this previously-proposed method, the tobacco was worked in a liquid phase and the leaching-out of substantial components of the tobacco was therefore unavoidable. Although at least part of the liquid was used later in the procedure it was not possible to ensure that all the valuable tobacco components removed by leaching were restored, so as to be present in the final product. This was particularly so as regards the tobacco components responsible for aroma and flavor.

In accordance with a further prior art method for the production of tobacco products, kwhole tobacco leaves, portions of tobacco leaves, or tobacco leaves cut into strips were to have finely divided tobacco or tobacco dust applied to them and attached by the means of adhesives, the purpose of the process being to use waste or woody ribs or the like from the tobacco leaves in the final product.

In accordance with a still further prior proposal, adhesives such as galactomannan gum, for example, were used for forming tobacco dust into a thin foil.

One object of the present invention is to provide a method of arranging a fibrous material and a dust-like material in a flat elongated formation without the use of any adhesives which do not originate from the tobacco plant.

3,496,255 Patented Feb. 17, 1970 ICC A further object of the invention is to provide such a method which does not involve the immersion of tobacco in a liquid phase.

A further object of the invention is to provide such a process which will make possible the manufacture of tobacco foil from tobacco dust with only a minimum amount of fibrous material.

A still further object of the invention is to provide a process for producing a tobacco foil which is substantially the same as tobacco.

Yet another object of the invention is to provide a method which can be generally used for arranging a fibrous material and a dust-like material in a flat elongated formation which is of general applicability, that is to say, not restricted to tobacco manufacture.

The present invention therefore consists in a process for arranging a fibrous material and a dust-like material in a flat elongated formation including the steps of freeing the dry fibrous material of lumps in a lump-removing supply means, drawing the material onto a moving conveyor belt by means of an electrostatic field extending between the supply means and the belt, maintaining the fibres on the belt in an on-end position in a zone downstream from the supply means, so that the dust comes to lie between the individual fibres of the fibrous material, and compacting the fibrous and dust-like material, preferably by rolling it. The elongated formation of fibrous and dust-like material can be slightly moistened before and/ or after compaction, or, alternatively, the w-hole process can be carried out in an atmosphere containing a suitable amount of moisture. This brings about a substantial increase in the tensile strength of the elongated formation produced.

The present invention also consists in an apparatus for forming an elongated formation of fibrous material and dust-like material, comprising an endless conveyor belt Iwith two parallel limbs, a lump-removing fibrous material supply means arranged opposite a particular limb of the conveyor belt, electrical lead means for maintaining an electrostatic field between the supply means and the conveyor belt, a plate extending along a portion of a particular limb of the conveyor belt downstream from the supply means for maintaining an electrostatic field along the particular limb, means for guiding dust-like material onto the conveyor belt limb opposite the field plate, and means for rolling the fibrous and dust-like materials to compact them.

Preferably the conveyor belt is grounded and the field plate and supply means are at a positive potential. Also, the field plate itself is preferably constructed as the means for guiding dust-like material onto the conveying belt and for this purpose is provided with holes directed towards the belt.

The removing of lumps from the fibrous material can be brought about by a rubbing or beating action. The starting fibrous material can for example be regenerated cellulose, hydrated cellulose, native cellulose, or other forms of treated cellulose or tobacco fibres.

The electrostatic field maintained between the conveyor belt and the field plate preferably has a potential gradient on the Order of 1000-2000 volts per centimeter, so that if the spacing is l0 cm. the potential will be at least about 10.000 v. or, if it is 20 cm., 20,000 v.

The moistening before and/or after compacting which increases the tensile strength of the foil produced can be done with water with or without tobacco extract, or possibly a solution of a binding agent. Such a binding agent can be a cellulose derivative such as CMC, MC methyl cellulose, ethyl cellulose, an alginate, pectin or galactomannans.

With the method in accordance with the invention it is not essential that the dust be applied to the fibrous material while the fibrous material is on end. It is only important that the fibrous material be aligned with the field so that it is perpendicular to the conveyor belt, with the dust-like material lying between the fibres and held between them during and after the following compaction.

Two embodiments of the invention are now described with reference to the accompanying drawing.

In the drawings:

FIG. 1 is a sectional side elevation of an apparatus for carrying out the invention.

FIG. 2 is a similar view of a further form of apparatus for carrying out the invention.

In both figures reference numerals 1 and 2 denote rolls or rollers on which a conveyor belt 3 is supported. The direction of movement of the conveyor belt is indicated by arrow 4. In the case of the embodiment of PIG. 1, a series of intermediate support rolls are Provided.

In both embodiments the rolls 2 are preferably grounded electrically.

The conveyor belt 3 is preferably made from a synthetic resin, or is of a material coated with a synthetic resin. It is also possible tomake the belt of metal, although this has been found to be less suitable than synthetic resin.

In the arrangement shown in FIG. 1, at the upstream end of the conveyor belt 3 there is a lump-removing comminuting supply means 5 for the fibrous material to be placed on the belt. This comprises a series of rolls 6, which may be provided with knives. The fibrous material freed of lumps emerges from the bottom end of the supply means 5, passes onto the conveyor belt 3, and travels in the direction denoted by arrow 4. The supply means 5 is maintained at a positive electrical potential while the conveyor belt 3 is grounded through the end roller 2, so that there is an electrostatic field between the supply means and the conveyor belt.

The fibrous material emerging from the outlet end of the supply means 5 drops onto the conveyor belt and passes underneath a field plate 7. The later carries a positive potental of, for example, 10,000 to 20,000 volts, which creates an electrostatic field between the plate and the conveyor belt 3. The field plate 7, which is electrically coupled with the supply means 5, has a plurality of holes 8 extending through it which enables it to serve as a sieve for the sprinkling of the dust-like material 9 onto the fibrous material already -on the belt 3, although other means can be provided for placing the dust-like material onto the fibrous material, for example by means blowing it in from the side.

Because of the electrostatic field between the conveyor belt 3 and the field plate 7, the individual fibres of the fibrous material stand on end, as shown diagrammatically at 10 inthe drawing. Thus, the dust-like material 9 settles downward and lies between the upright fibres 10. After leaving the electrostatic field formed between the upper run or branch of the conveyor belt and the field plate 7, the fibres of the fibrous-like material fall into a lying position, as is diagrammatically indicated by reference numeral 11. The fibrous layer or elongated formation charged with dust is then compacted between the roller 2 and a-n upper roller 12, and it then passes to the right as a comparatively strong web-like elongated formation 13 which is supported by rollers 14.

It has been found that the strength of the web or elongated formation 13 can be substantially increased if the formation is moistened additionally, as for example at position 11.

In the embodiment of the invention as shown in FIG. .2 the lump-removing supply means 5 is arranged below the lower run of the conveyor belt 3, and, as was the case with the first embodiment of the invention, is connected electrically with the field plate 7 extending downstream thereof. In this case, introduction of the dust-like material is carried out by means of nozzles 15 spaced along the length of the field plate and disposed between it and the conveyor belt, which operate to blow the dust-like material onto the belt from the side.

In the operation of this second embodiment, the electrostatic lfield causes the dust-like material to pass upwardly between the upright fibres 10 and against the belt 3, in which position this material will then remain so long as it is under the influence of the field. As the fibres and the dust-like material leave the field they are compacted together by a pair of opposed rollers 16, one of which is on each side of the belt, at position 17. The rollers 16 thus compact the material into an elongated fibre web or formation similar to that seen in FIG. 1 and designated by the numeral 13.

In general, an elongated web-like formation produced by the apparatus consists of from five to ten percent fibrous carrying material and approximately ninety percent dust-like material, that is to say, in the production of tobacco foils the proportion of tobacco dust can be at least ninety percent.

As will be understood, in those cases in which the apparatus of the invention is constructed with a conveyor belt 3 made of a non-chargeable material, a counterelectrode positioned opposite the field plate 7 can be proiclled, located between the upper and lower runs of the The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for arranging a fibrous material and a dust-like material in an elongated formation comprising the steps of: providing a source of dry fibrous material, transferring said fibrous material onto a moving conveyor means, applying dust-like material to said Conveyor means, subjecting both materials on said conveyor means to an electrostatic field to thereby bringing the fibers on the conveyor into an upright position in a zone downstream from the point of the supply of said fibers, such that the dust-like material lies between the upright individual fibers of the fibrous material, and compacting the fibrous and dust-like materials together.

2. A process according to claim 1, in which said fibrous material is transferred onto said conveyor means by drawing it toward the latter through the use of an electrostatic field.

3. A process according to claim 1, in which said dry fibrous material is made lump-free while being provided from its source.

4. A process according to claim 1, in which said dustlike material is applied to said conveyor by passing such material through said field in said zone.

5. A process according to claim 1, in which the fibrous material with the dust-like material are compacted by rolling.

`6. A process according to claim 1, in which the fibrous material and the dust-like material are moistened before compaction.

7. An apparatus for forming an elongated formation of fibrous material and dust-like material, comprising conveyor means having a movable conveyor member, means disposed adjacent said conveyor member for supplying fibrous material thereto, means disposed adjacent said conveyor member for supplying dust-like material thereto, so that said materials are commingled on said conveyor member, means effectively extending in a zone along a portion of the said conveyor member located downstreamfrom said material supply means for maintaining an electrostatic field along said conveyor member in said zone, and means for compacting the fibrous and dust-like materials together.

8. The apparatus of claim 7, further including lmeans for maintaining an electrostatic field between said means for supplying said fibrous material and said conveyor or member.

9. The apparatus of claim 7, wherein said means for maintaining said electrostatic lield in said zone comprise a charged plate extending generally parallel to said conveyor member and spaced apart therefrom at least slightly.

10. The apparatus of claim 7, wherein said movable conveyor member is of an electrically chargeable material.

11. The apparatus of claim 10, wherein said conveyor means includes a grounding circuit for maintaining said conveyor member at ground potential.

12. The apparatus of claim 9, wherein said plate further denes guide means for directing said dust-like material onto said conveyor member.

13. The apparatus of claim 9, further including means for maintaining an electrostatic iield between said means for supplying said brous material and said conveyor or member.

14. The apparatus of claim 13, wherein said movable conveyor member is of an electrically chargeable material.

15. The apparatus of claim 14, wherein said conveyor means includes a grounding circuit for maintaining said conveyor member at ground potential.

16. The apparatus of claim 15, wherein said plate further defines guide means for directing said dust-like material onto said conveyor member.

References Cited UNITED STATES PATENTS 2,217,444 10/1940 Hill .f 117-17 2,328,904 9/ 1943 Hiers 117-17 2,385,873 10/1945 Melton.

2,442,880 6/ 1948 Schwartz 264-24 2,468,827 5/ 1949 Kennedy et al.

2,675,330 4/ 1954 Schwartz et al. 117-17 2,820,716 1/1958 Harmon et al 11S-638 X 2,970,929 2/ 1961 Hansen et al 117-17 3,082,138 3/1963 Hjelt 117-17 3,426,730 2/ 1969 Lawson et al 118-636 SAMUEL KoREN, Primary Examiner DENNIS I. DONOHUE, Assistant Examiner U.S. C1. X.R. 

